xz-utils 4.999.9beta+20091016-1 (i386 binary) in ubuntu lucid

XZ is the successor to the Lempel-Ziv/Markov-chain Algorithm
compression format, which provides memory-hungry but powerful
compression (often better than bzip2) and fast, easy decompression.
.
This package provides the command line tools for working with XZ
compression, including xz, unxz, xzcat, xzgrep, and so on. They can
also handle the older LZMA format, and if invoked via appropriate
symlinks will emulate the behavior of the commands in the lzma
package.
.
The XZ format is similar to the older LZMA format but includes some
improvements for general use:
.
* 'file' magic for detecting XZ files;
* crc64 data integrity check;
* limited random-access reading support;
* improved support for multithreading (not used in xz-utils);
* support for flushing the encoder.